This application relates to a combination of two distinct engine types which can be efficiently utilized to drive a rotor.
Gas turbine engines are known and are used to drive a variety of aircraft. One known type of gas turbine engine is a so-called recuperated cycle engine. In such an engine, heat is captured and used to heat air downstream of a compressor prior to being delivered into a combustion section.
Another type of gas turbine engine is a simple cycle engine wherein such preheating does not occur.
Each type engine has its strengths.
Gas turbine engines have been utilized to drive rotary wing aircraft, such as a propeller system for a helicopter. Typically, a pair of engines are placed on the helicopter. Under certain conditions, drive from both of the engines is required. However, under many standard operating conditions, only one of the engines is sufficient to provide adequate power.
Pilots for such a rotary wing aircraft will often drive both engines as a safety measure.